If the number of moles of $\mathrm{Fe}^{2+}$ ions oxidised by one mole of acidified $\mathrm{MnO}_4^{-}$is $x$, the number of moles of $\mathrm{Fe}^{2+}$ ions oxidised by one mole of acidified $\mathrm{Cr}_2 \mathrm{O}_7^{2-}$ is

In acidic medium one mole each of $\mathrm{MnO}_4^{-}$and $\mathrm{Cr}_2 \mathrm{O}_7^{2-}$ is reduce by $x$ and $y$ moles of ferrous ions. The sum of $x$ and $y$ is

$\mathrm{C}+$ Conc. $\mathrm{H}_{2} \mathrm{SO}_{4} \xrightarrow{\Delta} X+Y+\mathrm{H}_{2} \mathrm{O}$

$X$ and $Y$ in the above reaction are

Observe the following reaction,

$ 2 \mathrm{KClO}_{3}(s) \xrightarrow{\Delta} 2 \mathrm{KCl}(\mathrm{~s})+3 \mathrm{O}_{2}(\mathrm{~g}) $

In this reaction